1 00:00:01,920 --> 00:00:06,400 Speaker 1: Welcome to Brainstuff the production of I Heart Radio, Hey, 2 00:00:06,440 --> 00:00:11,039 Speaker 1: brain Stuff. Lauren vocal bomb here it's the operatic equivalent 3 00:00:11,119 --> 00:00:14,120 Speaker 1: of the slip on the banana peal scene. The soprano 4 00:00:14,240 --> 00:00:17,040 Speaker 1: on stage hits a high note so long in piercing 5 00:00:17,200 --> 00:00:20,160 Speaker 1: that it cracks the opera glasses of the elegant Dowager 6 00:00:20,200 --> 00:00:23,319 Speaker 1: in the box seat. Hollywood can do that with a 7 00:00:23,320 --> 00:00:27,680 Speaker 1: trick of editing. But is it possible in real life? Well, 8 00:00:27,960 --> 00:00:31,120 Speaker 1: yes it is, but so is being struck by lightning. 9 00:00:31,560 --> 00:00:36,240 Speaker 1: Both require rare convergences of particular conditions and to understand 10 00:00:36,280 --> 00:00:38,960 Speaker 1: these conditions and how they work together a crash course 11 00:00:39,000 --> 00:00:45,240 Speaker 1: and acoustics is an order. Sound is acoustic energy, like electricity. 12 00:00:45,320 --> 00:00:49,080 Speaker 1: Sound energy travels through substances in waves, which excites these 13 00:00:49,080 --> 00:00:52,879 Speaker 1: substances particles and causes them to vibrate at a certain frequency. 14 00:00:53,159 --> 00:00:56,040 Speaker 1: A frequency refers to the number of waves passing through 15 00:00:56,080 --> 00:00:59,240 Speaker 1: a given point over a given period of time, and 16 00:00:59,280 --> 00:01:02,639 Speaker 1: we measure frequent see and hurts. One hurts equals one 17 00:01:02,640 --> 00:01:07,520 Speaker 1: wave per second. Meanwhile, every substance has a natural or 18 00:01:07,600 --> 00:01:12,200 Speaker 1: resonant frequency, the frequency at which its own molecules vibrate. 19 00:01:12,840 --> 00:01:16,520 Speaker 1: For example, suppose your bass guitar playing neighbor cracks the 20 00:01:16,520 --> 00:01:20,080 Speaker 1: plaster on your walls when they play a low driving baseline. 21 00:01:20,720 --> 00:01:23,240 Speaker 1: The quality of your neighbors speakers also affect the quality 22 00:01:23,240 --> 00:01:25,960 Speaker 1: of the sound, but basically, the frequency of a bass 23 00:01:26,000 --> 00:01:30,400 Speaker 1: guitar's lower deeper notes run from forty to fifty hurts, 24 00:01:30,480 --> 00:01:33,800 Speaker 1: and thus the plasters resonant frequency must fall somewhere in 25 00:01:33,840 --> 00:01:37,840 Speaker 1: that range. Because when a substance encounters a frequency it matches, 26 00:01:38,120 --> 00:01:43,160 Speaker 1: it absorbs the energy rather than reflecting it. Glass shattering 27 00:01:43,200 --> 00:01:47,760 Speaker 1: waves carry more energy they're shorter and choppier, thus more 28 00:01:47,800 --> 00:01:50,920 Speaker 1: of them pass through per second at roughly five hundred 29 00:01:50,920 --> 00:01:54,800 Speaker 1: and fifty six hurts. To shatter glass, the notes frequency 30 00:01:54,920 --> 00:01:57,360 Speaker 1: must be the same as that of the glass. That's 31 00:01:57,480 --> 00:02:02,200 Speaker 1: one condition. The note also has to be loud quality 32 00:02:02,240 --> 00:02:07,080 Speaker 1: known as intensity. Intensity is measured in decibels, while conversational 33 00:02:07,120 --> 00:02:10,480 Speaker 1: tones average fifty to sixty decibels. A trained vocalist might 34 00:02:10,520 --> 00:02:13,000 Speaker 1: have the pipes to approach the approximately a hundred and 35 00:02:13,000 --> 00:02:16,920 Speaker 1: five decibels needed to break glass. Even then they would 36 00:02:16,919 --> 00:02:19,840 Speaker 1: have to be so close as to risk serious facial cuts. 37 00:02:19,840 --> 00:02:23,200 Speaker 1: If the glass does explode, more likely a boost of 38 00:02:23,240 --> 00:02:28,880 Speaker 1: electronic amplification would be needed. Finally, the glass must be 39 00:02:28,960 --> 00:02:32,799 Speaker 1: strategically selected. A wine glass is a good choice. It's 40 00:02:32,880 --> 00:02:37,240 Speaker 1: fine and thin, unlike say beer stein, which maximizes the 41 00:02:37,240 --> 00:02:41,400 Speaker 1: amount of stress per particle. An empty glass cracks more readily, 42 00:02:41,520 --> 00:02:45,200 Speaker 1: although less dramatically than one containing water or wine air, 43 00:02:45,400 --> 00:02:49,280 Speaker 1: being less dense, the liquid carries the sound better, and 44 00:02:49,480 --> 00:02:51,360 Speaker 1: if you can find a wine glass with a flaw 45 00:02:51,360 --> 00:02:54,480 Speaker 1: in its structure, even an invisible one, that helps by 46 00:02:54,480 --> 00:03:00,320 Speaker 1: providing a weak spot. Incidentally, real world tests involving resident 47 00:03:00,360 --> 00:03:04,320 Speaker 1: frequencies offer more than an excuse to shatter glass. Resident 48 00:03:04,400 --> 00:03:07,839 Speaker 1: frequency is the basis of ultrasonic testing, which is used 49 00:03:07,880 --> 00:03:11,639 Speaker 1: to determine the safety of structures ranging from pipelines to airplanes. 50 00:03:12,240 --> 00:03:15,600 Speaker 1: Ultrasonic testing is a type of non destructive testing which 51 00:03:15,639 --> 00:03:19,480 Speaker 1: allows engineers to monitor the integrity of construction materials as 52 00:03:19,639 --> 00:03:23,360 Speaker 1: where and while they're being used, which is preferable to 53 00:03:23,639 --> 00:03:28,720 Speaker 1: otherwise dismantling a building or airplane for analysis in a laboratory. 54 00:03:33,320 --> 00:03:35,720 Speaker 1: Today's episode is based on the article can You really 55 00:03:35,720 --> 00:03:37,760 Speaker 1: Shatter a Glass? With a high note on how stuff 56 00:03:37,760 --> 00:03:40,680 Speaker 1: works dot com, written by Christine Benzen. Brain Stuff is 57 00:03:40,680 --> 00:03:42,480 Speaker 1: a production of by Heart Radio in partnership with how 58 00:03:42,520 --> 00:03:44,720 Speaker 1: stuff Works dot Com, and it's produced by Tyler Clang. 59 00:03:45,160 --> 00:03:47,720 Speaker 1: Four more podcasts my heart Radio, visit the i heart 60 00:03:47,760 --> 00:03:50,400 Speaker 1: Radio app, Apple Podcasts, or wherever you listen to your 61 00:03:50,440 --> 00:03:51,120 Speaker 1: favorite shows.